java - 如何使用 Java 在 Eclipse 中使用 Web 服务(JAX - RS)从数据库中检索数据

标签 java mysql eclipse jersey jax-rs

我已将一条记录插入数据库，但我不知道如何检索它。 我的代码是: 账户.java:

package com.fetch;

import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Id;

public class Account implements Serializable 
{   
  @Id
  private long id;

  @Column(name="NAME")  
  private String name;

  public Account()  
  {

  }

  public Account(int id, String name)   
  {     
     this.id = id;      
     this.name = name;  
  }

  public long getId() 
  {     
     return id; 
  }

  public void setId(long id) 
  {     
     this.id = id;  
  }

  public String getName() 
  {     
     return name;   
  }

  public void setName(String name)
  {     
     this.name = name;  
  }
}

我的账户.java:

package com.fetch;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.Collection;
import javax.jws.WebMethod;
import javax.jws.WebService;
import javax.persistence.Entity;
import javax.persistence.NamedQuery;
import javax.persistence.Table;
import javax.ws.rs.FormParam;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.Path;

@WebService()
@Entity
@Table(name = "CUSTOMER")
@Path("/user")
@NamedQuery(name="loginquery", query="select ID,NAME from CUSTOMER")
public class MyAccount 
{   
   private Account ac;  
   public MyAccount()   
   {    
     // TODO Auto-generated constructor stub      
     ac = new Account();    
   }    

   @POST    
   @Path("/fetch")  
   @WebMethod(operationName = "insert") 
   public String insert(@FormParam("name") String name) 
   {     
      try   
      {     
         Class.forName("com.mysql.jdbc.Driver");        
         Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/studentinfo", "root", "root");

         String query = "insert into CUSTOMER"+"(NAME) VALUES"+"(?)";
     PreparedStatement st = con.prepareStatement(query);    
         st.setString(1,name);  
     st.executeUpdate();
      }     
      catch (Exception e)   
      {     
         System.out.println(e.getMessage());    
      } 
      return"Record inserted successfully";
   }    
  public Account getAc() 
  {     
     return ac; 
  } 
  public void setAc(Account ac) 
  {     
     this.ac = ac;  
  }
}

插入.html:

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert</title>
</head>
<body>
    <form action="rest/user/fetch" method="POST">
        <p>
            Name : <input id="name" name="name" />
        </p>
        <input type="submit" value="Add" />
            <input type="submit" value="Retrive" />
    </form>
</body>
</html>

web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
   <display-name>FetchAndInsert</display-name>
   <servlet>
      <servlet-name>REST Servlet</servlet-name>
      <servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
      <init-param>
         <param-name>com.sun.jersey.config.property.packages</param-name>
         <param-value>com.fetch</param-value>
      </init-param>
      <load-on-startup>1</load-on-startup>
   </servlet>
   <servlet-mapping>
      <servlet-name>REST Servlet</servlet-name>
      <url-pattern>/rest/*</url-pattern>
   </servlet-mapping>
</web-app>

当用户点击检索按钮时，如何从数据库中检索数据，并以另一个HTML 表单显示所有记录？ 请就如何操作给出建议。

在我的应用程序中，当用户单击检索按钮时，它正在执行插入操作。 但我想要的是，当用户点击它时，它应该转到另一个页面并显示数据库表中的数据。

谁能告诉我我所做的错误，并给出解决方案的建议，以及当用户单击检索按钮时如何在其他页面显示动态表？

最佳答案

我终于完成了，现在我可以使用 jersey(JAX - RS) web 服务从数据库中插入和检索数据，并能够在 html 页面中显示它。

账户.java:

package com.fetch;

import java.io.Serializable;
import javax.persistence.Column;
import javax.persistence.Id;

public class Account implements Serializable 
{
    @Id
    private long id;

    @Column(name = "NAME")
    private String name;

    public Account(int id, String name)
    {
        this.id = id;
        this.name = name;
    }
    public long getId() {
        return id;
    }
    public void setId(long id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}

我的账户.java:

package com.fetch;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import javax.jws.WebMethod;
import javax.jws.WebService;
import javax.persistence.Entity;
import javax.ws.rs.FormParam;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;

@WebService()
@Entity
@Path("/user")
public class MyAccount
{
    @POST
    @Path("/fetch")
    @WebMethod(operationName = "insert")
    public String insert(@FormParam("name") String name) 
    {
        try 
        {
            Class.forName("com.mysql.jdbc.Driver");
            Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/studentinfo", "root", "root");
            String query = "insert into CUSTOMER"+"(NAME) VALUES"+"(?)";

            PreparedStatement st = con.prepareStatement(query);
            st.setString(1,name);
            st.executeUpdate();     
        } 
        catch (Exception e) 
        {
            System.out.println(e.getMessage());
        }
        return"Record inserted successfully";
    }

    @GET
    @Path("/retrive")
    @Produces("text/html")
    @WebMethod(operationName = "retrive")
    public String retrive() 
    {
        ResultSet rs = null;
        String details = ""; 
        try 
        {
            Class.forName("com.mysql.jdbc.Driver");
            Connection con = DriverManager.getConnection("jdbc:mysql://localhost:3306/studentinfo", "root", "root");

            String query = "select ID,NAME from CUSTOMER";

            PreparedStatement st = con.prepareStatement(query);
            rs = st.executeQuery();

            details = "<html><body>"; 
            details = details + "<table border=1>";
            details = details + "<tr><td><Strong>Id </Strong></td>" +
                                    "<td><Strong>Name </Strong></td>" + "</tr>";
            while (rs.next()) 
            {
                details = details + "<tr><td>" + rs.getInt("ID") + "</td>" +
                                        "<td>" + rs.getString("NAME") + "</td></tr>";
            }
            details += "</table></body></html>"; 
        } 
        catch (Exception e) 
        {
            System.out.println(e.getMessage());
        }   
        return details;
    }
}

插入.html:

 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert</title>
</head>
<body>
    <form action="rest/user/fetch" method="POST">
        <p>
            Name : <input id="name" name="name" />
        </p>
        <input type="submit" value="Add" />
    </form>
    <form action="rest/user/retrive" method="GET">
        <input type="submit" value="Retrive" />
    </form>
</body>
</html>

我的 web.xml 是:

 <?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    id="WebApp_ID" version="3.0">
    <display-name>FetchAndInsert</display-name>
    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
    <servlet>
        <servlet-name>REST Servlet</servlet-name>
        <servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
        <init-param>
            <param-name>com.sun.jersey.config.property.packages</param-name>
            <param-value>com.fetch</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>REST Servlet</servlet-name>
        <url-pattern>/rest/*</url-pattern>
    </servlet-mapping>
</web-app>

关于java - 如何使用 Java 在 Eclipse 中使用 Web 服务(JAX - RS)从数据库中检索数据，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/10091499/

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